This invention relates to a process for the manufacture of half bearings with flanges rigidly connected thereto. The invention also relates to the bearings obtained by said process.
In various applications, and mainly for pivotally supporting the crankshafts of internal combustion engines, it is necessary to use radial bearings integrated by flanges acting as thrust bearings, and owing to assembly requirements the bearings must be subdivided in two parts. Half bearings and separate flanges may be used for each pivotal supporting point, but this method requires the separate installation of three components and therefore it gives rise to long working times and it is not suitable for mechanized assembly processes. Half bearings have been proposed, to which the respective flanges, in the form of half rings, are weakly secured by means of slightly fixed joints. These half bearings with flanges weakly secured thereto allow reducing the manual assembly times, but they are still not suitable for a mechanized assembly process, due to the insufficient resistance of the connection between the half rings and the half bearing. The mechanical grasping devices used in mechanized assembly operations cannot grasp the pieces with a human sensibility, and they often damage the pieces if these are not of a sufficient sturdiness.
To allow a mechanized assembly, half bearings with integral flanges are normally used, which are obtained from a steel sheet plaque coated, on one of its faces, with an antifriction material. However, the manufacture of such a complex piece from a plane coated plaque requires a long process of gradual bending with simultaneous bulging, which leads to very high production costs. In view of reducing these costs it has been proposed to separately manufacture the half bearing and the two half rings, and then to connect these three components by means of folded seamings. However, the seaming operations give rise to considerable deformations of the parts, so that both the half bearing with integral flanges and the half bearing with seamed flanges have to be subjected to the finishing operations when they already have assumed their complex final configuration; this implies the use of complex and expensive equipment, and long working times, and accordingly high production costs.